"Secondly I was always taught NEVER to repeat the "clear" part of a clearance as it could be mistaken by another aircraft for their clearance."
That was ONCE the case; however, it had changed by the early 1990s. It then became MANDATORY to repeat the word 'clear' afer ATC had used it. You ARE TO readback all clearances.
When I came back to QFI-ing on the VC10 after some QFI-ing on the Bulldog, I found that some of my colleagues hadn't kept up with the changes and were still advocating the use of the word 'ROGER' after ATC called 'Clear to land'. Or even the 'click-click' on RT.
"I'm not an expert and have never read JSP blah de blah . I just fly aeroplanes."
I would say that is an unprofessional attitude. I suggest you go and read 'JSP blah de blah' and improve your professionalism if you're not flying!